Wheat blast, a fast-acting and devastating fungal disease, has been reported for the first time on the African continent, according to a new article published by scientists from the Zambian Agricultural Research Institute (ZARI), the International Maize and Wheat Improvement Center (CIMMYT) and the US Department of Agriculture – Foreign Disease Weed Science Research Unit (USDA-ARS) in the scientific journal PLoS One.

Symptoms of wheat blast first appeared in Zambia during the 2018 rainy season in experimental plots and small-scale farms in the Mpika district, Muchinga province.

Wheat blast poses a serious threat to rain-fed wheat production in Zambia and raises the alarm for surrounding regions and countries on the African continent with similar environmental conditions. Worldwide, 2.5 billion consumers depend on wheat as a staple food, and in recent years, several African countries have been actively working towards reducing dependence on wheat imports.

“This presents yet another challenging biotic constraint to rain-fed wheat production in Zambia,” said Batiseba Tembo, wheat breeder at ZARI and lead scientist on the study.

A difficult diagnosis

“The first occurrence of the disease was very distressing. This happened at the spike stage, and caused significant losses,” said Tembo. “Nothing of this nature has happened before in Zambia.”

Researchers were initially confused when symptoms of the disease in the Mpika fields were first reported. Zambia has unique agro-climatic conditions, particularly in the rainfed wheat production system, and diseases such as spot blotch and Fusarium head blight are common.

“The crop had silvery white spikes and a green canopy, resulting in shriveled grains or no grains at all…Within the span of 7 days, a whole field can be attacked,” said Tembo. Samples were collected and analyzed in the ZARI laboratory, and suspicions grew among researchers that this may be a new disease entirely.

A history of devastation

Wheat blast, caused by Magnaporthe oryzae pathotype Triticum (MoT), was initially discovered in Brazil in 1985, and within decades had affected around 3 million hectares of wheat in South America alone. The disease made its first intercontinental jump to Asia in 2016, causing a severe outbreak in Bangladesh, reducing yield on average by as much as 51% in the affected fields.

The disease has now become endemic to Bangladesh, and has potential to expand to similar warm, humid and wet environments in nearby India and Pakistan, as well as other regions of favorable disease conditions.

Wheat blast spreads through infected seeds and crop residues as well as by spores that can travel long distances in the air. The spread of blast within Zambia is indicated by both mechanisms of expansion.

Developing expert opinions

Tembo participated in the Basic Wheat Improvement Course at CIMMYT in Mexico, where she discussed the new disease with Pawan Singh, head of Wheat Pathology at CIMMYT.  Singh worked with Tembo to provide guidance and the molecular markers needed for the sample analysis in Zambia, and coordinated the analysis of the wheat disease samples at the USDA-ARS facility in Fort Detrick, Maryland.

All experiments confirmed the presence of Magnaporthe oryzae pathotype Triticum (MoT).

“This is a disaster which needs immediate attention,” said Tembo. “Otherwise, wheat blast has the potential to marginalize the growth of rain-fed wheat production in Zambia and may threaten wheat production in neighboring countries as well.”

A cause for innovation and collaboration

CIMMYT and the CGIAR Research Program on Wheat (WHEAT) are taking action on several fronts to combat wheat blast. Trainings, such as an international course led by the Bangladesh Wheat and Maize Research Institute (BWMRI) in collaboration with CIMMYT, WHEAT and others, invite international participants to gain new technical skills in blast diagnostics and treatment and understand different strategies being developed to mitigate the wheat blast threat. WHEAT scientists and partners are also working quickly to study genetic factors that increase resistance to the disease and develop early warning systems, among other research interventions. 

“A set of research outcomes, including the development of resistant varieties, identification of effective fungicides, agronomic measures, and new findings in the epidemiology of disease development will be helpful in mitigating wheat blast in Zambia,” said Singh.

Tembo concluded, “It is imperative that the regional and global scientific community join hands to determine effective measures to halt further spread of this worrisome disease in Zambia and beyond.”

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Read the study:

Detection and characterization of fungus (Magnaporthe oryzae pathotype Triticum) causing wheat blast disease on rain-fed grown wheat (Triticum aestivum L.) in Zambia

Interview opportunities:

Pawan Kumar Singh, Senior Scientist and Head of Wheat Pathology (CIMMYT)

Batiseba Tembo, Wheat Breeder, Zambian Agricultural Research Institute (ZARI) batemfe@yahoo.com

For more information, or to arrange interviews, contact the media team:

Rodrigo Ordóñez, Communications Manager (CIMMYT) r.ordonez@cgiar.org

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Acknowledgements

Financial support for this research was provided by the Zambia Agriculture Research Institute (ZARI), the CGIAR Research Program on Wheat (WHEAT), the Australian Centre for International Agricultural Research (ACIAR), and the US Department of Agriculture’s Agricultural Research Service (USDA-ARS). 

The Basic Wheat Training Program and Wheat Blast Training is made possible by support from investors including ACIAR, WHEAT, the Indian Council of Agricultural Research (ICAR), Krishi Gobeshona Foundation (KGF), the Swedish Research Council (SRC) and the United States Agency for International Development (USAID).

About CIMMYT

The International Maize and What Improvement Center (CIMMYT) is the global leader in publicly-funded maize and wheat research and related farming systems. Headquartered near Mexico City, CIMMYT works with hundreds of partners throughout the developing world to sustainably increase the productivity of maize and wheat cropping systems, thus improving global food security and reducing poverty. CIMMYT is a member of the CGIAR System and leads the CGIAR programs on Maize and Wheat and the Excellence in Breeding Platform. The Center receives support from national governments, foundations, development banks and other public and private agencies. For more information visit www.cimmyt.org.

The CGIAR Research Program on Wheat (WHEAT) has “a track record of delivering local solutions with a global perspective — and is well positioned to continue this trajectory in the next decade.”

This was a key finding of a recent review of the program aimed to assess WHEAT’s 2017-2019 delivery of quality science and effectiveness, as well as to provide insights and lessons to inform the program’s future.

“Wheat as a crop is bound to be central to global food security in the foreseeable future,” the reviewers stated.

The crop currently contributes 20% of the world population’s calories and protein—and global demand is estimated to increase by 44% between 2005-07 and 2050.

WHEAT — led by the International Maize and Wheat Improvement Center (CIMMYT) with the International Center for Agricultural Research in the Dry Areas (ICARDA) as a key research partner —has two pillars that are essential to meeting this demand: raising potential yield through breeding and closing the yield gap through sustainable intensification at field, farm and landscape scales.

Key recommendations included supporting strategic investment in research partner network development and maintenance, and continuing WHEAT’s trajectory towards modernizing breeding processes and integrating sustainable intensification approaches, including mechanization.

The reviewers warned of challenges for the way ahead, pointing out that partnerships — and WHEAT’s reputation as a reliable partner — are vulnerable to funding volatility. The review also raised concerns about the potential fragmentation of the global breeding program, restrictions to the international exchange of germplasm and ideas, “misguided” emphasis on minor crops, and CGIAR’s “focus on process at the expense of results.”

“This review cuts to the core of what’s so critical—and at risk – not only with our program but wheat research in general,” said Hans Braun, director of the CIMMYT Global Wheat Program and the CGIAR Research Program on Wheat. “Global collaboration and the exchange of improved seeds, data, and especially information.”

“The reviewers rightly point out that limited resources will lead to competition and dampen this collaboration—even between scientists in the same program. We must address this potential risk to improve integration and continue our life saving work.” 

“In most of the developing world, the alliance of public sector and CGIAR wheat breeding programs, as well as some national public breeding programs on their own, will remain dominant providers of wheat varieties, until either functioning seed royalty collection systems are established and/or hybrid wheat becomes a reality,” he added.

WHEAT’s strength is its robust global network of research for development partners and scientists linked to global breeding in a ‘wide adaptation’ approach,” said Victor Kommerell, program manager for the CGIAR Research Programs on Wheat and Maize.

“This review underscores that breaking up the breeding program could cause lasting damage to this network.”

More key findings include:

• WHEAT is effective and well-managed: In 2017- 2019, WHEAT mainly achieved its planned outputs and outcomes, and in addition achieved unplanned outcomes. For the three years reviewed, WHEAT did not drop any research line.

• WHEAT’s strength is its partnerships: WHEAT has catalyzed a global network of research and development (R&D) that has delivered and continues to deliver a disproportionate wealth of outputs in relation to investment.

• WHEAT creates, and thrives on, collaboration: The predominantly public nature of wheat R&D (In the period 1994–2014, the public sector accounted for 63% of global wheat varietal releases and more than 95% of releases in developing countries) favors collaboration, compared with other industries.

• WHEAT facilitates shared success: The long history of collaboration between CIMMYT, ICARDA and national partners has fostered a sense of belonging to the International Wheat Improvement Network that permits free exchange of information and germplasm, allowing the best varieties to be released, irrespective of origin. International nursery testing delivers elite lines for national program use; data shared by national programs informs WHEAT’s next crossing cycle.

Read more in a 2-page brief summarizing key findings, conclusions and recommendations or on the CGIAR Advisory Services page.

A team of scientists has found desirable traits in wheat’s extensive and unexplored diversity.

This press release was originally posted on the website of the International Maize and Wheat Improvement Center (CIMMYT).

Researchers working on the Seeds of Discovery (SeeD) initiative, which aims to facilitate the effective use of genetic diversity of maize and wheat, have genetically characterized 79,191 samples of wheat from the germplasm banks of the International Maize and Wheat Improvement Center (CIMMYT) and the International Center for Agricultural Research in the Dry Areas (ICARDA).

The findings of the study published today in Nature Communications are described as “a massive-scale genotyping and diversity analysis” of the two types of wheat grown globally — bread and pasta wheat — and of 27 known wild species.

Wheat is the most widely grown crop globally, with an annual production exceeding 600 million tons. Approximately 95% of the grain produced corresponds to bread wheat and the remaining 5% to durum or pasta wheat.

The main objective of the study was to characterize the genetic diversity of CIMMYT and ICARDA’s internationally available collections, which are considered the largest in the world. The researchers aimed to understand this diversity by mapping genetic variants to identify useful genes for wheat breeding.

From germplasm bank to breadbasket

The results show distinct biological groupings within bread wheats and suggest that a large proportion of the genetic diversity present in landraces has not been used to develop new high-yielding, resilient and nutritious varieties.

“The analysis of the bread wheat accessions reveals that relatively little of the diversity available in the landraces has been used in modern breeding, and this offers an opportunity to find untapped valuable variation for the development of new varieties from these landraces”, said Carolina Sansaloni, high-throughput genotyping and sequencing specialist at CIMMYT, who led the research team.

The study also found that the genetic diversity of pasta wheat is better represented in the modern varieties, with the exception of a subgroup of samples from Ethiopia.

The researchers mapped the genomic data obtained from the genotyping of the wheat samples to pinpoint the physical and genetic positions of molecular markers associated with characteristics that are present in both types of wheat and in the crop’s wild relatives.

According to Sansaloni, on average, 72% of the markers obtained are uniquely placed on three molecular reference maps and around half of these are in interesting regions with genes that control specific characteristics of value to breeders, farmers and consumers, such as heat and drought tolerance, yield potential and protein content.

Open access

The data, analysis and visualization tools of the study are freely available to the scientific community for advancing wheat research and breeding worldwide.

“These resources should be useful in gene discovery, cloning, marker development, genomic prediction or selection, marker-assisted selection, genome wide association studies and other applications,” Sansaloni said.

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Read the study:

Diversity analysis of 80,000 wheat accessions reveals consequences and opportunities of selection footprints.

Interview opportunities:

Carolina Sansaloni, High-throughput genotyping and sequencing specialist, CIMMYT.

Kevin Pixley, Genetic Resources Program Director, CIMMYT.

For more information, or to arrange interviews, contact the media team:

Ricardo Curiel, Communications Officer, CIMMYT. r.curiel@cgiar.org

Rodrigo Ordóñez, Communications Manager, CIMMYT. r.ordonez@cgiar.org

Acknowledgements:

The study was part of the SeeD and MasAgro projects and the CGIAR Research Program on Wheat (WHEAT), with the support of Mexico’s Secretariat of Agriculture and Rural Development (SADER), the United Kingdom’s Biotechnology and Biological Sciences Research Council (BBSRC), and CGIAR Trust Fund Contributors. Research and analysis was conducted in collaboration with the National Institute of Agricultural Botany (NIAB) and the James Hutton Institute (JHI).

About CIMMYT:

The International Maize and What Improvement Center (CIMMYT) is the global leader in publicly-funded maize and wheat research and related farming systems. Headquartered near Mexico City, CIMMYT works with hundreds of partners throughout the developing world to sustainably increase the productivity of maize and wheat cropping systems, thus improving global food security and reducing poverty. CIMMYT is a member of the CGIAR System and leads the CGIAR programs on Maize and Wheat and the Excellence in Breeding Platform. The Center receives support from national governments, foundations, development banks and other public and private agencies. For more information visit www.cimmyt.org.

A new quantitative genetics study makes a strong case for the yield testing strategies the International Maize and Wheat Improvement Center (CIMMYT) uses in its wheat breeding program.

The process for breeding for grain yield in bread wheat at the International Maize and Wheat Improvement Center (CIMMYT) involves three-stage testing at an experimental station in the desert environment of Ciudad Obregón, in Mexico’s Yaqui Valley. Because the conditions in Obregón are extremely favorable, CIMMYT wheat breeders are able to replicate growing environments all over the world, and test the yield potential and climate-resilience of wheat varieties for every major global wheat growing area. These replicated test areas in Obregón are known as selection environments (SEs).

This process has its roots in the innovative work of wheat breeder and Nobel Prize winner Norman Borlaug, more than 50 years ago.  Wheat scientists at CIMMYT, led by wheat breeder Philomin Juliana, wanted to see if it remained effective.

The scientists conducted a large quantitative genetics study comparing the grain yield performance of lines in the Obregón SEs with that of lines in target growing sites throughout the world. They based their comparison on data from two major wheat trials: the South Asia Bread Wheat Genomic Prediction Yield Trials in India, Pakistan and Bangladesh initiated by the U.S. Agency for International Development Feed the Future initiative, and the global testing environments of the Elite Spring Wheat Yield Trials.

The findings, published in Retrospective Quantitative Genetic Analysis and Genomic Prediction of Global Wheat Yields, in Frontiers in Plant Science, found that the Obregón yield testing process in different SEs is very efficient in developing high-yielding and resilient wheat lines for target sites.

The authors found higher average heritabilities, or trait variations due to genetic differences, for grain yield in the Obregón SEs than in the target sites (44.2 and 92.3% higher for the South Asia and global trials, respectively), indicating greater precision in the SE trials than those in the target sites.   They also observed significant genetic correlations between one or more SEs in Obregón and all five South Asian sites, as well as with the majority (65.1%) of the Elite Spring Wheat Yield Trial sites. Lastly, they found a high ratio of selection response by selecting for grain yield in the SEs of Obregón than directly in the target sites.

“The results of this study make it evident that the rigorous multi-year yield testing in Obregón environments has helped to develop wheat lines that have wide-adaptability across diverse geographical locations and resilience to environmental variations,” said Philomin Juliana, CIMMYT associate scientist and lead author of the article.

“This is particularly important for smallholder farmers in developing countries growing wheat on less than 2 hectares who cannot afford crop losses due to year-to-year environmental changes.”

In addition to these comparisons, the scientists conducted genomic prediction for grain yield in the target sites, based on the performance of the same lines in the SEs of Obregón. They found high year-to-year variations in grain yield predictabilities, highlighting the importance of multi-environment testing across time and space to stave off the environment-induced uncertainties in wheat yields.

“While our results demonstrate the challenges involved in genomic prediction of grain yield in future unknown environments, it also opens up new horizons for further exciting research on designing genomic selection-driven breeding for wheat grain yield,” said Juliana. 

This type of quantitative genetics analysis using multi-year and multi-site grain yield data is one of the first steps to assessing the effectiveness of CIMMYT’s current grain yield testing and making recommendations for improvement—a key objective of the new Accelerating Genetic Gains in Maize and Wheat for Improved Livelihoods (AGG) project, which aims to accelerate the breeding progress by optimizing current breeding schemes.

This work was made possible by the generous support of the Delivering Genetic Gain in Wheat (DGGW) project funded by the Bill & Melinda Gates Foundation and the UK Foreign, Commonwealth & Development Office (FCDO) and managed by Cornell University; the U.S. Agency for International Development’s Feed the Future initiative; and several collaborating national partners who generated the grain yield data.

Read the full article here: https://doi.org/10.3389/fpls.2020.580136

New research platform focuses on helping smallholder farmers sustainably increase production and adapt to climate change, reducing yield and efficiency gaps in major crops

Nine CGIAR centers, supported by the Big Data Platform, launched the Excellence in Agronomy 2030 initiative today at the African Green Revolution Forum (AGRF) online summit.

The Excellence in Agronomy 2030 (EiA 2030) initiative will assist millions of smallholder farmers to intensify their production systems while preserving key ecosystem services under the threat of climate change. This initiative, co-created with various scaling partners, represents the collective resolve of CGIAR’s agronomy programs to transform the world’s food systems through demand- and data-driven agronomy research for development.

EiA 2030 will combine big data analytics, new sensing technologies, geospatial decision tools and farming systems research to improve spatially explicit agronomic recommendations in response to demand from scaling partners. Our science will integrate the principles of Sustainable Intensification and be informed by climate change considerations, behavioral economics, and scaling pathways at the national and regional levels.

A two-year Incubation Phase of EiA 2030 is funded by the Bill & Melinda Gates Foundation. The project will demonstrate the added value of demand-driven R&D, supported by novel data and analytics and increased cooperation among centers, in support of a One CGIAR agronomy initiative aiming at the sustainable intensification of farming systems.

Speaking on the upcoming launch, the IITA R4D Director for Natural Resource Management, Bernard Vanlauwe, who facilitates the implementation of the Incubation Phase, said that “EiA 2030 is premised on demand-driven agronomic solutions to develop recommendations that match the needs and objectives of the end users.”

Christian Witt, Senior Program Officer from the Bill & Melinda Gates Foundation, lauded the initiative as a cornerstone for One CGIAR. “It is ingenious to have a platform like EiA 2030 that looks at solutions that have worked in different settings on other crops and whether they can be applied in a different setting and on different crops,” Witt said.

Martin Kropff, Director General of the International Maize and Wheat Improvement Center (CIMMYT), spoke about the initiative’s goals of becoming the leading platform for next-generation agronomy in the Global South, not only responding to the demand of the public and private sectors, but also increasing efficiencies in the development and delivery of solutions through increased collaboration, cooperation and cross-learning between CGIAR centers and within the broader agronomy R&D ecosystem, including agroecological approaches.

CGIAR centers that are involved in EiA include AfricaRice, the International Center for Tropical Agriculture (CIAT), the International Maize and Wheat Improvement Center (CIMMYT), the International Potato Center (CIP), the International Center for Agricultural Research in the Dry Areas (ICARDA), World Agroforestry Center (ICRAF), the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), the International Institute of Tropical Agriculture (IITA), and the International Rice Research Institute (IRRI)

This press release was originally posted on the website of the Borlaug Global Rust Initiative (BGRI).

As the world grapples with a disastrous human health crisis, scientists will gather virtually October 7-9 to discuss strategies to safeguard the health of one of the planet’s most important food sources — wheat.

The Borlaug Global Rust Initiative’s (BGRI) virtual technical workshop will bring together scientists at the forefront of wheat science for cutting-edge training and knowledge sharing. Experts from global institutions such as Cornell University, the International Maize and Wheat Improvement Center (CIMMYT), the International Center for Agricultural Research in the Dry Areas (ICARDA), and the John Innes Centre, with presenters from Ethiopia, Kenya, India, Australia, Finland, Mexico, the United Kingdom and United States, will lead in-depth talks and discussions on the most pressing challenges facing global wheat security.

Event registration is now open.

“Right now we are witnessing the devastation that the global spread of disease can cause, and it underscores the continual threat that diseases pose to our most important food crops,” said Ronnie Coffman, vice-chair of the BGRI and an international professor in Cornell’s Department of Global Development and School of Integrative Plant Science. “Devastating wheat epidemics would be catastrophic to human health and wellbeing. October’s workshop is an opportunity for wheat scientists to converge virtually for the practical training and knowledge-sharing we need to fight numerous challenges.”

The three-day workshop in October will be broken up into sessions with keynotes from leading experts and presentations focused on key areas of wheat research:

• Breeding technologies
• Disease surveillance
• Molecular host-pathogen interaction
• Disease resistance
• Gene stewardship

The BGRI is a strong proponent of responsible gene deployment to ensure the efficacy of disease resistant genes available to breeders. Since 2012, the BGRI has bestowed the Gene Stewardship Award in recognition of excellence in the development, multiplication and/or release of rust resistant wheat varieties that encourage diversity and complexity of resistance. The winners of the 2020 BGRI Gene Stewardship award will be announced at the workshop.

Maricelis Acevedo, associate director for science for the Delivering Genetic Gain in Wheat (DGGW) project and researcher in Cornell’s Department of Global Development, said: “The BGRI has been at the forefront of developing the next generation of wheat warriors, especially in strengthening the technical and professional skills of women and men scientists from developing countries. We are taking a global approach to help reduce the threat of diseases that can overwhelm farmers’ wheat fields. Issues related to improving world food security, especially in the face of climate change, can only be addressed by a diverse and united global community.”

She added: “The BGRI’s technical workshop has long been the premiere meeting ground for wheat scientists around the world. It’s more important than ever that we come together to address the challenges before us.”

The BGRI 2020 Technical Workshop originally planned for June 1-4 in Norwich, United Kingdom was postponed due to COVID-19.

Wheat is one of the world’s largest primary commodity, with global production of over 700 million tons, grown on over 215 million hectares. Eaten by over 2.5 billion people in 89 countries, wheat provides 19% of the world’s total available calories and 20% of all protein.

Over the past 20 years, the global area under wheat production has not increased. To produce the required amount of wheat needed to feed the world’s growing population, researchers predict wheat yields must increase at least 1.4% per acre through 2030.

Wheat faces pressure from the changing environment and diseases, especially rust diseases increasingly prevalent in wheat-growing regions everywhere. The BGRI was formed in 2005 in response to a novel strain of rust discovered in East Africa known as Ug99 that posed risks of epidemic proportions to global wheat production. Norman Borlaug galvanized global scientists and donors in a bid to combat Ug99 and other disease pressures.

“The world averted disaster thanks to the commitment of researchers and farmers from all over the world who participated in the BGRI’s coordinated global response,” said Coffman. “With the backing of far-sighted donors, the BGRI focused on delivering rust-resilient varieties of wheat to farmers around the world, and dedicating our efforts to small-holder farmers in wheat-producing countries in Africa and Asia — men and women who do not always have access to new technologies and improved seed.” 

Registration page is now live.

The BGRI is a community of hunger fighters dedicated to protecting the world’s wheat. The initiative receives funding through the DGGW project, supported by the Bill & Melinda Gates Foundation and the UK Foreign, Commonwealth & Development Office.

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The new director of the CGIAR Research Program on Wheat brings many years of experience in wheat genetics, wheat genetic resources and wheat pre-breeding.

This story by Marta Millere was originally published on the CIMMYT website.

In November 2020, Alison Bentley will be joining the International Maize and Wheat Improvement Center (CIMMYT) as the new director of the Global Wheat Program and the CGIAR Research Program on Wheat (WHEAT). She will be succeeding Hans Braun, who has steered CIMMYT’s Global Wheat Program for the last 16 years, and has led the CGIAR Research Program on Wheat since its establishment in 2014.

Bentley expressed that she is thrilled to join CIMMYT and excited about the opportunity to harness science and breeding to improve livelihoods. She believes in a collective vision for equitable food supply and in science-led solutions to deliver impact.

“It really is an exciting time for wheat research: the international community has worked together to produce sequence and genomic resources, new biological and physiological insights, a wealth of germplasm and tools for accelerating breeding. This provides an unparalleled foundation for accelerating genetic gains and connecting ideas to determine how we can practically apply these tools and technologies with partners to deliver value-added outputs,” she said.

Bentley has worked on wheat — wheat genetics, wheat genetic resources and wheat pre-breeding — her entire career. She is the UK’s representative on the International Wheat Initiative Scientific Committee, and is a committee member for the Genetics Society, the UK Plant Sciences Federation, the Society of Experimental Botany, and the Editorial Board of Heredity.

Bentley obtained her PhD from the University of Sydney, Australia, in 2007. She then joined the National Institute of Agricultural Botany (NIAB) in the UK, where she progressed from Senior Research Scientist (2007) to Program Leader for Trait Genetics (2013), and Director of Genetics and Breeding (since 2016).

Currently, Bentley is involved in international research projects in Ethiopia, The Gambia, Ghana, India and Pakistan. She leads a number of UK-India projects with partners including Punjab Agricultural University, the Indian National Institute of Plant Genome Research and the University of Cambridge, studying variation and developing wheat and other cereal germplasm with enhanced resource use efficiency.

This article by Sakshi Saini was originally published on the CCAFS website. 

Ever-increasing emissions of greenhouse gases (GHG) is a global concern due to the association of high atmospheric GHG concentrations with global warming and climate change. A large and growing body of evidence predicts that this would further have a multifaceted impact on the human population, especially the poor and vulnerable groups, further exacerbating their vulnerabilities.

But what about crops? Plants use carbon dioxide (CO₂)—one of the most abundant GHGs, for photosynthesis. So shouldn’t an increase in atmospheric carbon dioxide aid crops to flourish? A counter-argument to this would be that at the same time there would be changes in other factors such as a change in precipitation rate, frequency and intensity of rains, among others, which might negatively impact crop production. So, how exactly would climatic variations impact the yield and productivity of crops? These are some of the questions that have been a global concern. Many studies have researched this, employing varied approaches such as systems biology, physiology and crop modelling. However, unprecedented changes in climatic conditions still pose uncertainties on the impacts on crops.

Recent research by an interdisciplinary team of scientists from the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), the CGIAR Research Program on Climate Chanage, Agriculture and Food Security (CCAFS)-Africa and CCAFS-Asia aspires to answer some of these questions. As part of this research, they have compiled recent progress made in the physiological and molecular attributes in plants, with special emphasis on legumes under elevated CO₂ conditions in a climate change scenario. The study proposes a strategic research framework for crop improvement that integrates genomics, systems biology, physiology and crop modelling approaches to cope with the changing climate. Some of the prime results of the study are as follows:

1. Major physiological and biochemical alterations in legumes triggered by elevated CO2

A range of physiological and biochemical alterations take place in plants exposed to elevated CO₂. In the case of legumes, elevated atmospheric CO₂ concentrations also affect the nutritional quality and nodulation, causes changes in rhizosphere and Biological Nitrogen Fixation (BNF), among others. Studies have shown that elevated CO₂ would stimulate plant growth under nitrogen-sufficient conditions, but under nitrogen-limited conditions, it may have the detrimental effect of reducing plant growth by altering its primary metabolism. The anatomical differences between C3 and C4 plants (plants with C3 and C4 photosynthetic pathways) and their different ways of sequestering carbon (removing carbon dioxide from the atmosphere), have been an area of interest for climate scientists. Elevated CO₂ combined with limited nitrogen may also promote biological ageing (senescence) rates as observed in flag leaves of rice and wheat. Studies also show that a higher level of carbon dioxide increases senescence rate in legumes.

2. Impact of elevated carbon-dioxide interaction with other abiotic stresses

As mentioned earlier, CO₂ is not the only factor that is impacting plant growth, it is dependent on other environmental factors such as water deficit stress and temperature, among others. Thus, these factors also need to be considered in combination with the atmospheric concentration. Studies have reported that elevated CO₂ induced a decrease (of 10%) in evaporation rates in both C3 and C4 plants. This caused an increase in canopy temperature (0.7 °C) coupled with a 19% yield increase in C3 crops. There is evidence that an increase in CO₂ has also phased down the effect of oxidative stress. Though, there is limited literature available about the impact of elevated carbon dioxide keeping into consideration the drought and heat responses of various crops.

3. Elevated carbon dioxide and its interaction with biotic stress-altered pathogen aggravation and virulence

The changing climate has affected pest-crop dynamics with more frequent outbreaks and changed the geographical distribution of pests, posing an economic threat to crops. Sometimes, other abiotic stresses like drought could increase fungal virulence as reported in drought-tolerant peanut and Aspergillus interaction. However, a combined interaction is not always additive as both unique and common responses have been observed. Increased CO₂ causes greater photosynthate availability, but reduced foliage quality along with an increased concentration of plant defensive compounds after a pest infestation. This, in turn, affects insect feeding and increases disease incidence and predator parasitism interactions.

4. Molecular interventions for crop improvement under elevated carbon-dioxide

While elevated CO₂ may cause greater photosynthate availability, the interaction of elevated CO₂ with mentioned biotic and abiotic stresses calls for the development of climate change ready crop varieties. Thus, genomics assisted breeding along with other modern approaches can be very powerful tools to develop superior varieties, to de-risk the existing food system. This transformative approach towards the production of plants and crops would be instrumental in sustainably ensuring food security.

An integrated research framework for the future

The discussion and evidence presented illustrate that the effect of elevated CO₂ under a changing climate scenario is multifaceted and aggravated by the overlapping interaction of stressors. The notion that CO₂ has beneficial effects in terms of increased productivity is now being questioned since the photosynthetic fertilization effect is short term and often not time-tested for major crop species. The IPCC 2018 special report highlights several policy-level approaches that are aimed at limiting greenhouse gas emission. The scientific community needs to be prepared with suitable research outcomes to cope with the effects of elevated atmospheric CO2 levels. In this regard, an integrated framework combining different biological disciplines has been proposed by the team (Fig. 1).

While significant advances have been made in crop genomics, systems biology and genomics-assisted breeding, the success of trait dissection and trait deployment is very much dependent on the quality and precision of phenotyping. Recent advances in plant phenotyping using high throughput phenotyping tools have revolutionized the uptake of phenotype and allelic information in a more precise and robust way and complemented high throughput genomic resources

In the opinion of the authors of the publication, an integrated research framework that includes genomics/ systems biology and phenomics together with crop modelling would result in faster data-driven advances for understanding the optimal GxExM (genotype x environment x management) scenarios for current and projected climates. Interdisciplinary approaches as has been done through the Climate-Smart Village approach, are key to graduating from a descriptive level to an improved quantitative and process-level understanding of sustainable crop productivity.

Read more:

• Journal article: An integrated research framework combining genomics, systems biology, physiology, modelling and breeding for legume improvement in response to elevated CO2 under climate change scenario

Rajiv Kumar Sharma on insecurity, rural isolation and challenge of supporting crop production in a conflict zone.

by Emma Orchardson

In September 2002, looters raided the storage facilities housing Afghanistan’s largest collection of crop genetic material. In the towns of Ghazni and Jalalabad, hundreds of samples of the country’s rich agricultural heritage were lost as wheat, barley, pistachio and pomegranate seeds were ripped from the plastic containers designed to preserve them. The incident was described as a tragic loss, with representatives from the United Nations lamenting the fact that these lost varieties were essential genetic resources for sustaining future food production in a country where farmers struggle to withstand harsh climatic conditions such as recurrent drought.

Nearly two decades later, these climatic challenges have been further compounded by demographic ones, as rising population and income levels fuel consumption of some of the country’s most important cereal crops, including wheat – which makes up around 60% of the nation’s daily caloric intake – and maize. Failure to meet domestic demand could have devasting consequences in a country whose growth and economy are dominated by agriculture.

Some of Afghanistan’s obstacles to crop production are not unique. Poor market support, limited mechanization and inadequate storage stifle growing and processing activities from Latin America to South Asia. Others – such as rain dependent wheat and grossly deficient extension services – are more specific to a country in the midst of ongoing and widespread conflict. As anti-government forces continue to target transport infrastructure and police road travel between provinces, links between the nation’s pockets of relative urban security and the 70% of Afghans who live and work in rural areas are drastically reduced.

Farmers beyond reach

“Insecurity is by far the biggest hurdle in communication with and reaching out to farmers,” says Rajiv Kumar Sharma, the International Maize and Wheat Improvement Center’s (CIMMYT) Country Representative for Afghanistan.

The organization has been operating in the country since 2002, supporting national agricultural research systems through the provision of germplasm, support for data collection and analysis, and working to release high-yielding, disease resistant crop varieties into the Afghan seed system and farmers’ fields. While capacity development for local research partners has been extremely successful, connecting directly with farmers remains practically impossible in many areas.

Sharma points to the results of a 2016 survey on the adoption of new improved maize and wheat varieties and crop management practices under local conditions, which found much higher adoption rates among farmers who had received some form of training or who had access to markets and a main road. “However, because even the most basic transport facilities are missing in most places, during our field visits or meetings it was not unusual to hear from farmers that it was the first time they had ever met their extension workers.”

“It’s a very complicated situation,” he explains. “We cannot look at any one factor in isolation because everything is interconnected – insecurity, governance, infrastructure, logistics, access to roads, transport and markets.”

Even the country’s seed market, he adds, seems to be an artificial one. “I used to say that the seed market was donor-driven because they would give money to the government, who would purchase all the seed produced and distribute among farmers. But once that system dwindled around 2014/15, seed production came down. If production is not remunerative, farmers simply aren’t going to invest.”

In the face of limited resources and capacity, non-available irrigation services, collapsed industry and a fragile economy, Sharma highlights the lack of infrastructure as the main limiting factor in developing the country’s seed sector. “It matters because it really impacts the extent to which we can reach people.”

“Did you know, for example, that Afghanistan did not have a postal system until few years ago and the one present today is not fully functioning. Can you imagine how much effort it takes for us just to move our seed packets and data sheets from one province to another?”

With no functioning courier services and limited public transport between cities, trial data dispatches are sent across the country using private taxi services. There are obvious and imaginable challenges involved in working in a conflict zone, he explains, but realities on the ground are often more challenging than what you’d expect.

Successes with seed

It’s not all doom and gloom in Kabul though, and Sharma remains optimistic about the progress of CIMMYT’s work in Afghanistan despite the numerous challenges. “It’s not easy working here, but still we can do something.”

Recent successes include the release of four new high yielding and disease resistant wheat varieties in early 2020 and the successful culmination of the “Improving food security by enhancing wheat production and its resilience to climate change through maintaining the diversity of currently grown landraces” project in December 2019. Funded by the International Treaty on Plant Genetic Resources for Food and Agriculture, the project supported the collection, characterization and evaluation of the country’s landraces and relied heavily on dedicated local staff and their ability to navigate the territory as safely as possible. “They know where they can and can’t go, as well as the dynamics and how to protect themselves,” Sharma explains.

In the northwestern provinces of Balkh and Herat, staff were able to collect landraces from farmer fields for testing against modern improved varieties at research stations. The team were then able to remove those susceptible to disease, purify the superior ones and improve them with regards to variability and uniformity. They found that, on average, Afghan wheat landraces yielded highest under rainfed conditions when compared with those from Iran and Turkey, as well as against winter wheat trials carried out in 2018.

These landraces have since been used in breeding improvement and crossing programs, as well as being multiplied and given back to local communities. “This has really enriched regional variability and made these landraces more useful for those communities who grow them and thus contribute to conserving useful variability on farm.”

This story by Alison Doody was originally published on the CIMMYT website.

It was the site where International Maize and Wheat Improvement Center (CIMMYT) scientist Norman Borlaug famously received news of his 1970 Nobel Peace Prize win. Now, Toluca station will become CIMMYT’s new testing site for rapid generation advancement and speed breeding in wheat – a method that accelerates generation advancement of crops and shortens the breeding cycle using tools like continuous lighting and temperature control.

The Toluca wheat experimental station is one of CIMMYT’s five experimental stations in Mexico, located in a picturesque town on the outskirts of Mexico’s fifth largest city, Toluca, about 60 kilometers southwest of Mexico City. The station was strategically chosen for its cool, humid conditions in summer. These conditions have made it an ideal location for studying wheat resistance to deadly diseases including yellow rust and Septoria tritici blotch.

Since its formal establishment in 1970, Toluca has played a key role in CIMMYT’s wheat breeding program. The site is also of significant historical importance due to its origins as a testing ground for Borlaug’s shuttle breeding concept in the 1940s, along with Ciudad Obregón in the Sonora state of northern Mexico. The breeding method allowed breeders to plant at two locations to advance generations and half the breeding cycle of crops.

Applying this unorthodox breeding method, Borlaug was able to advance wheat generations twice as fast as standard breeding programs. Planting in contrasting environments and day lengths — from the cool temperatures and high rainfall of Toluca to the desert heat of Ciudad Obregón — also allowed Borlaug and his colleagues to develop varieties that were more broadly adaptable to a variety of conditions. His shuttle breeding program was so successful that it provided the foundations of the Green Revolution.

Toluca was also the site where the first sexual propagation of the destructive plant pathogen Phytophtora infestans was reported. The deadly pathogen is best known for causing the potato late blight disease that triggered the Irish potato famine.

New life for the historic station

More than 50 years since its establishment, the station will once again host cutting-edge innovation in wheat research, as the testing ground for a new speed breeding program led by wheat scientists and breeders from Accelerating Genetic Gains in Maize and Wheat (AGG).

Funded by the Bill & Melinda Gates Foundation, the UK Department for International Development (DFID), the U.S. Agency for International Development (USAID) and the Foundation for Food and Agriculture Research (FFAR), AGG aims to accelerate the development and delivery of more productive, climate-resilient, gender-responsive, market-demanded, and nutritious maize and wheat varieties.

While most breeding programs typically take between 7-8 years before plants are ready for yield testing, shuttle breeding has allowed CIMMYT to cut the length of its breeding programs in half, to just 4 years to yield testing. Now, AGG wheat breeders are looking to shorten the breeding cycle further, through rapid generation advancement and speed breeding.

“The AGG team will use a low-cost operation, in-field screenhouse, spanning 2 hectares, to grow up to 4 generations of wheat per year and develop new germplasm ready for yield testing within just 2 years,” said Ravi Singh, CIMMYT distinguished scientist and head of wheat improvement. “This should not only save on cost but also help accelerate the genetic gain due to a significant reduction in time required to recycle best parents.”

Construction of the new rapid generation advancement and speed breeding facilities is made possible by support from the Bill and Melinda Gates Foundation and DFID through Delivering Genetic Gain in Wheat (DGGW), a 4-year project led by Cornell University, which ends this year. It is expected to be complete by September.

The concept of speed breeding is not new. Inspired by NASA’s efforts to grow crops in space, scientists at the University of Sydney, the University of Queensland (UQ) and the John Innes Centre developed the technique to accelerate the development of crops and improve their quality. The breeding method has been successfully used for crops like spring wheat, barley, pea, chickpea, radish and canola.

CIMMYT Global Wheat Program Director Hans Braun highlighted the importance of testing the new breeding scheme. “Before completely adopting the new breeding scheme, we need to learn, optimize and analyze the performance results to make necessary changes,” he said.

If all goes well, Toluca could once again be on the vanguard of wheat research in the near future.

“We plan to use the speed breeding facility for rapid integration of traits, such as multiple genes for resistance, to newly-released or soon to be released varieties and elite breeding lines,” said CIMMYT Wheat Breeder Suchismita Mondal, who will lead the work in these facilities. We are excited to initiate using the new facilities.”